Method and device for folding back tire structure member

ABSTRACT

To effectively restrict occurrence of radially extending grooves in tire sidewall portions, turn-up portions (N) of a tire structure member (K) are turned up around the beads (B) by synchronously moving turn-up arms ( 66 ) axially inward by a moving means ( 75 ), with turn-up rollers ( 70 ) maintained in contact with the turn-up portion (N), and simultaneously, by synchronously swinging the turn-up arms ( 66 ) radially outward by a swinging means ( 76 ). The contact pressure of the turn-up rollers ( 70 ) applied to the turn-up portion (N) can thus be easily adjusted to an optimum value, with the result that impressions (grooves) produced in the outer surface of the turn-up portion (N) (which becomes part of the tire sidewall portion after being turned up) can be kept as shallow as possible.

TECHNICAL FIELD

The present invention relates to a method and an apparatus for turningup a tire structure members, wherein a substantially cylindrical turn-upportion of the tire structure member located on both outsides of beadportions in the axial direction is turned around the bead so as toextend along a main body portion of a substantially semicircular shape,which is located between the beads.

BACKGROUND ART

Conventional method and apparatus for turning up a tire structure memberare disclosed, for example, in JP2001-525748A. This known apparatusincludes a plurality of turn-up arms which are arranged as being spacedfrom each other in the peripheral direction, on both axially outer sidesof a tire building drum. The turn-up arms are adapted to swing in theradial direction around the respective base ends separated from a beadlock body in a plane including the center axis of the tire buildingdrum. A turn-up roller is rotatably supported by the tip end of eachturn-up arm and adapted to achieve a rolling contact with the turn-upportion. A rubber band is fitted to the outside of the turn-up arms sothat the turn-up arms are applied with urging swing force orientedradially inward. A moving means is provided for synchronously moving theturn-up arms axially inward, to thereby cause the turn-up arms tosynchronously swing radially outward against the rubber band while theturn-up rollers are maintained in rolling contact with the turn-upportions, so that the turn-up portions are turned around the beads.

However, in such conventional method and apparatus for turning up a tirestructure member, when the turn-up portion is turned, the swingingmovement of the turn-up arm radially outward is performed by applying amoving force to the turn-up arm axially inward, so that the turn-uprollers are made to ascend along the main body portion. At this time,since the turn-up arms are swung against the resilient force of therubber band, the turn-up rollers are strongly urged against the turn-upportions under a large reaction force from the rubber band. As a result,impressions (grooves) extending in the radial direction is generated inthe outer surface of the turn-up portion. Such impressions tend to beconsiderably deep and cannot be erased even by vulcanization in somecases, giving rise to a problem that grooves extending in the radialdirection are generated in sidewall portions of a product tire.

It is an object of the present invention to provide a method and anapparatus for turning up a tire structure member, capable of effectivelyrestricting generation of grooves in a sidewall portion.

DISCLOSURE OF THE INVENTION

To this end, the present invention in its first aspect provides a methodfor turning up a tire structure member, wherein a pair of beads aresupported by a tire building drum from radially inside, andsubstantially cylindrical turn-up portions of the tire structure memberlocated on axially outside of the beads are turned around the beads toextend along a main body portion of the tire structure member locatedbetween the beads and having a substantially semicircular cross-section,with an apparatus including a plurality of turn-up arms spaced from eachother in a peripheral direction and arranged on both outsides of thetire building drum in the axial direction, said turn-up arms each beingadapted to swing in the radial direction around a base end spaced fromthe bead on a plane including the center axis of the tire building drum,and further including turn-up roller rotatably supported by tip ends ofthe turn-up arms, wherein the turn-up arms are moved synchronously by amoving means axially inward, with said turn-up rollers maintained incontact with the turn-up portion, while said turn-up arms are swungsynchronously by a swinging means radially outward so that the turn-upportions are turned around the bead.

The present invention in its second aspect provides an apparatus forturning up a tire structure member, wherein a pair of beads aresupported by a tire building drum from radially inside, andsubstantially cylindrical turn-up portions of the tire structure memberlocated on axially outside of the beads are turned around the beads toextend along a main body portion of the tire structure member locatedbetween the beads and having a substantially semicircular cross-section,said apparatus comprising: a plurality of turn-up arms spaced from eachother in a peripheral direction and arranged on both outsides of thetire building drum in the axial direction, said turn-up arms each beingadapted to swing in the radial direction around a base end spaced fromthe bead on a plane including the center axis of the tire building drum;a plurality of turn-up rollers rotatably supported by tip ends of theturn-up arms and adapted to achieve rolling contact with the turn-upportion; a moving means for synchronously moving the turn-up arms in theaxial direction; and a swinging means for synchronously swinging theturn-up arms in the radial direction, wherein the turn-up arms are movedsynchronously by a moving means axially inward, with said turn-uprollers maintained in contact with the turn-up portion, while saidturn-up arms are swung synchronously by a swinging means radiallyoutward so that the turn-up portions are turned around the bead.

According to the present invention, in order that the turn-up portion ofthe tire structure member is turned around the bead, the turn-up armsare synchronously moved by the moving means axially inward, with theturn-up rollers maintained in contact with the turn-up portion, and theturn-up arms are synchronously swung by the swinging means radiallyoutward. Therefore, the contact pressure of the turn-up rollers againstthe turn-up portion can be easily adjusted to an optimum value, and theimpressions (grooves) generated in the outer surface of the turn-upportion (to be a part of the tire sidewall portion after being turnedup) can be made as shallow as possible. As a result, the above-describedgrooves cab be substantially erased by vulcanization, and generation ofthe grooves extending in the radial direction on the sidewall portion ofa product tire can be easily and effectively restricted.

The turning up apparatus for a tire structure member according to thepresent invention may be designed so that the moving means comprises aninner slider which is movable in the axial direction, and the swingingmeans comprises an outer slider slidably fitted in the inner slider andoverlapped with the inner slider at least at its axially inner end, aplurality of links each having an inner end connected to the innerslider and an outer end rotatably connected to a center part in thelongitudinal direction of each turn-up arm, and a moving mechanism foraxially moving the outer slider relative to the inner slider. It isthereby possible to maintain the pressing force against the turn-upportion constant regardless of elapse of the time, to secure a stabletire quality, and to simplify the structure allow manufacturing at lowcost.

Additionally, the turning up apparatus for a tire structure memberaccording to the present invention may be designed so that the movingmechanism comprises a cylinder chamber formed between the inner sliderand the outer slider, and a supply/discharge passage for supplying ordischarging a fluid to or from the cylinder chamber. It is therebypossible to reduce the entire axial length of the apparatus as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view, as seen from the front side, illustrating apreferred embodiment of the present invention.

FIG. 2 is a sectional view thereof, in enlarged scale.

BEST MODE FOR CARRYING-OUT OF THE INVENTION

A preferred embodiment of the present invention will be described belowwith reference to the drawings.

In FIGS. 1 and 2, reference numeral 11 denotes a tire building drum forbuilding green tire thereon. The tire building drum 11 includes ahorizontal main shaft 12 of cylindrical shape. The drum main shaft 12 isconnected to a driving portion of a tire building machine (not shown),and driven into rotation about the axis by the driving portion, whenevernecessary.

A screw shaft 13 coaxial with the drum main shaft 12 is loosely androtatably fitted in the drum main shaft 12. The screw shaft 13 can berotated by a driving motor, not shown, independently of the drum mainshaft 12. Male screw portions 14, which are inverse screws, are providedon the outer circumference of the screw shaft 13 on both sides in theaxial direction, respectively. Slits 15 extending in the axial directionare formed in the drum main shaft 12 along its portions overlapping themale portions 14. Reference numeral 16 denotes a nut that is inthread-engagement with each male screw portion 14. Each nut 16 is fixedto a connecting block 17 penetrating into the slit 15.

Reference numeral 20 denotes substantially cylindrical sliders which arefitted from outside on both axial sides of the drum main shaft 12 so asto be movable in the axial directions. The connecting blocks 17 areconnected to the sliders 20, respectively. As a result, when the screwshaft 13 is driven into rotation by the driving motor, the sliders 20are moved by equal distance in the opposite directions by means of themale screw portions 14 in the form of inverse screws, toward and awayfrom each other.

The axially inner end of each slider 20 is integrally connected to abottom wall of a cylinder case portion 21 of cylindrical shape, which isclosed by a bottom. The cylinder case portion 21 has an opening at itsaxially outer end, which is substantially closed by a substantiallyannular guide flange 22 fixed thereto. A plurality of guide rails 23extending in the radial direction are provided on the axially outer sideof the guide flange 22, which are spaced from each other at an equalinterval in the peripheral direction.

Reference numeral 24 denotes a plurality of bead lock segments arrangedin the peripheral direction with an equal interval. Slide bearings 25are fixed to the bead lock segments 24, which are slidably engaged withthe guide rails 23. The above-described plurality of bead lock segments24 placed on one side, as a whole, constitute a bead lock body 26. As aresult, a pair of the bead lock bodies 26 are provided on the tirebuilding drum 11 as being spaced from each other in the axial direction.

Each bead lock segment 24 has a radially outer end, which is formed withan arcuate lock groove 27 for locking a bead B with a filler F fromradially inside, through a tire structure member K comprising a carcassply H and side treads J adhered to both ends of the carcass ply H in thewidth direction. It is assumed that the tire structure member K has beenformed into the cylindrical shape at another molding drum, the conveyedby a conveying means (not shown) together with the pair of beads B, withthe fillers F set at predetermined positions outside the both axial endsof the tire structure member K, and loosely fitted onto the tirebuilding drum 11.

On this occasion, the sliders 20 of the tire building drum 11 are movedaway from each other, to the axially outer limit positions by therotation of the screw shaft 13, while the bead lock bodies 26 areretracted to the radially inner limit positions, and the beads B withthe fillers F are set outside in the radial direction of the bead lockbodies 26. In this condition, when the bead lock body 26 projectsradially outward, the tire structure member K, in particular the carcassply H, is held from both sides, between the bead lock body 26 and thebead B with the filler F.

Subsequently, the sliders 20 are moved together axially inward, by therotation of the screw shaft 13 at a constant speed. When high-pressurefluid is supplied into the tire structure member K between the beads B,i.e., into the main body portion M, the tire structure member K betweenthe beads B (i.e., the main body portion M) expands radially outward tohave the substantially semicircular sectional shape, though the turn-upportion N on axially outside from the bead B maintains the cylindricalshape. Also, the bead lock segment 24 axially outside from the lockgroove 27 is formed with a receiving surface 28 having an arcuatesection inclined radially inward as it extends axially outward, suchthat the receiving surfaces 28 are engaged by turn-up rollers to bedescribed hereinafter.

At the inner end in the axial direction of each slider 20, there isdefined a cylinder chamber 29 surrounded by the slider 20, inclusive ofthe cylinder case portion 21 and the guide flange 22. Each cylinderchamber 29 axially movably accommodates an annular piston 31, whichdivides the above cylinder chamber 29 into an inner cylinder chamber 29Aand an outer cylinder chamber 29B. Reference numeral 32 denotescylindrical sliders each having an axially inner end integrallyconnected to the radially inner end of the piston 31. Each slider 32 isslidably fitted to the outer peripheral surface of the slider 20 and theinner peripheral surface of the guide flange 22. When the high pressurefluid is supplied to the inner cylinder chamber 29A, the piston 31 andthe slider 32 are integrally moved axially outward. On the contrary,when the high pressure fluid is supplied to the outer cylinder chamber29B, they are integrally moved axially inward.

Reference numeral 34 denotes a plurality of (the same in number as thebead lock segments 24) links each having an outer end rotatablyconnected to the bead lock segment 24, and an inner end connected to theaxially outer end of the slider 32 located axially outside from theguide flange 22. These links 34 are inclined so as to opened axiallyinward. When the piston 31 and the slider 32 are moved axially inward,as described above, the bead lock segments 24 are synchronously movedradially outward while being guided by the guide rail 23. On thecontrary, when the piston 31 and the slider 32 are moved axiallyoutward, the bead lock segments 24 are synchronously moved radiallyinward.

Reference numeral 36 denotes readily deformable seal members with asubstantially V-shaped section, each having its base end air-tightlyfixed between the cylinder case portion 21 and the guide flange 22. Whenthe bead B is supported from radially inside by the bead lock segments24 through the tire structure member K, the tip end of the seal member36 is clamped between the bead lock segments 24 and the tire structuremember K. Thus, sealing is achieved between the guide flange 22 and thebead lock segment 24 and between the bead lock segment 24 and the tirestructure member K.

Each slider 20 has an annular flange 39 on its outer surface in theaxially center region, which is externally fitted with an inner slider40 of substantially cylindrical shape, with the inner peripheral surfacein sliding contact with the outer peripheral surface of the flange 39 soas to be movable in the axial direction. Each inner slider 40 has anaxially inner end, which is provided with an annular inner end wall 41extending radially inward. The inner end wall 41 has an inner peripheralsurface in sliding contact with the outer peripheral surface of theslider 20 axially inside from the flange 39. As a result, a cylinderchamber 42 is formed between the slider 20 including the flange 39, andthe inner slider 40 including the inner end wall 41.

Reference numeral 44 denotes a fluid passage formed within each slider20. The fluid passage 44 has one end connected to a fluid source, andanother end in communication with the cylinder chamber 42. As a result,when the high pressure fluid is supplied from the fluid source into thecylinder chamber 42 through the fluid passage 44, the inner slider 40 ismoved axially inward. On this occasion, the inner slider 40 engages anouter slider to be described hereinafter, thereby causing the latter tobe moved integrally. Also, the inner slider 40 in its axially outer endhas an annular outer end wall 47 extending radially inward, so that anannular clearance is formed between the inner periphery of the outer endwall 47 and the outer periphery of the slider 20.

Reference numeral 44 denotes a fluid passage formed within each slider20. The fluid passage 44 has one end connected to a fluid source, andanother end in communication with the cylinder chamber 42. As a result,when the high pressure fluid is supplied from the fluid source into thecylinder chamber 42 through the fluid passage 44, the inner slider 40 ismoved axially inward. On this occasion, the inner slider 40 engages anouter slider to be described hereinafter, thereby causing the latter tobe moved integrally. Also, the inner slider 40 in its axially outer endhas an annular outer end wall 47 extending radially inward, so that anannular clearance is formed between the inner periphery of the outer endwall 47 and the outer periphery of the slider 20.

Reference numeral 50 denotes a substantially cylindrical outer sliderhaving an axial length smaller than that of the inner slider 40. Theouter slider 50 axially extends through the clearance between the outerwall portion 47 of the inner slider 40 and the slider 20, and isslidably fitted in the inner periphery of the outer wall portion 47 andthe outer periphery of the slider 20. Since the outer slider 50 extendsthrough the clearance between the outer wall portion 47 and the slider20 as mentioned above, the outer slider 50 overlaps the inner slider 40in the radial direction at least at its axially inner end.

The outer slider 50 has an axially inner end provided with an annularinner end wall 51 extending radially outward and having an outerperiphery in sliding contact with the inner periphery of the innerslider 40. As a result, a cylinder chamber 52 is formed between theslider 20 including the flange 39, the inner slider 40, and the innerend wall 51 of the outer slider 50. Reference numeral 54 denotes fluidpassages formed within the respective sliders 20. Each fluid passage 54has one end connected to a fluid source, and another end incommunication with the cylinder chamber 52. As a result, when the highpressure fluid is supplied from the fluid source into the cylinderchamber 52 through the fluid passage 54, the outer slider 50 is movedaxially outward. On this occasion, the outer slider 50 can be engaged bythe inner slider 40 and thereby integrally moved axially outward.

A cylinder chamber 56 is formed between the inner slider 40 includingthe outer end wall 47, and the outer slider 50 including the inner endwall 51. The cylinder chamber 56 is connected to the fluid sourcethrough a fluid hose 57 and a communication hole 58 in the outer endwall 47. As a result, when the high pressure fluid is supplied from thefluid source into the cylinder chamber 56 through the fluid hose 57 andthe communication hole 58, the outer slider 50 is moved axially inwardrelative to the inner slider 40, thereby increasing the overlappingamount of the outer and inner sliders 50 and 40.

The above-described fluid hose 57 and the communication hole 58, as awhole, constitute a supply/discharge passage 59 for supplying ordischarging the fluid to or from the cylinder chamber 56. Also, theabove-described cylinder chamber 56 and the supply/discharge passage 59,as a whole, constitute a moving mechanism 62 for axially moving theouter slider 50 relative to the inner slider 40. By constituting themoving mechanism 62 with the cylinder chamber 56 and thesupply/discharge passage 59 in this way, it is possible to reduce theaxial length of the entire apparatus.

A plurality of brackets 65, sixty in number in the illustratedembodiment, which is more than twice of the conventional number, aremounted on the outer periphery at the axially outer end of each outerslider 50 and arranged in the circumferential direction with an equalinterval. Reference numeral 66 denotes a plurality of turn-up arms (thesame in number as that of the brackets 65) placed respectively on theboth axially outer sides of the tire building drum 11. These turn-uparms 66 are arranged in the circumferential direction with an equalinterval. Each turn-up arm has a base end (the axially outer end)separated from the relevant bead lock body 26 and bent at right angles.The base end of the turn-up arm 66 is pivotally connected to the outerslider 50 through a pin 67 and the bracket 65. As a result, the turn-uparms 66 are capable of swing in the radial direction about the pin 67located at the base end on the plane including the center axis of thetire building drum 11.

Turn-up rollers 70 are rotatably supported at the tip ends (axiallyinner ends) of the turn-up arms 66 close to the relevant bead lock body26. These turn-up rollers 70 can be brought into rolling contact withthe relevant turn-up portion N of the tire structure member K (i.e., theinner peripheral surface when it is in the cylindrical state), about therotational axes parallel to the center axis of the pin 67. Since thenumber of the turn-up rollers 70 is sixty, which is more than twice ofthe conventional number, the pressing force applied to the turn-upportion N is dispersed and generation of impressions is restricted,besides that the turn-up portion N can be effectively turned-up atincreased points.

When the above turn-up arms 66 are swung radially outward while beingmoved axially inward, the turn-up rollers 70 serve to turn thecylindrical turn-up portion N radially outward around the bead B, alongthe main body portion M with the substantially semicircular section.

Reference numeral 72 denotes a plurality of links (same in number asthat of the turn-up arms 66) each extending linearly and having an innerend pivotally connected to the outer periphery of the inner slider 40 atits axially inner end. Each link 72 has an outer end pivotally connectedto the longitudinal center portion of the turn-up arm 66. As a result,when the high pressure fluid is supplied to the cylinder chamber 56 andthe outer slider 50 is thereby moved axially inward relative to theinner slider 40, the turn-up arms 66 are synchronously swung radiallyoutward about the respective base ends (pins 67) while being restrictedby the links 72.

The inner slider 40, the cylinder chambers 42, 52 and the fluid passages44, 54, as a whole, constitute a moving means 75 for synchronouslymoving the turn-up arm 66 in the axial directions. Similarly, the outerslider 50, the moving mechanism 62 and the link 72, as a whole,constitute a swinging means 76 for synchronously swinging the turn-uparms 66 in the radial directions. The moving means 75 and the swingingmeans 76 operate simultaneously when turning the turn-up portions N.

Here, when the moving means 75 is comprised of the inner sliders 40, thecylinder chambers 42, 52 and the fluid passages 44, 54, and the swingingmeans 76 is comprised of the outer sliders 50, the moving mechanisms 62and the links 72, as described above, they are constructed onlymechanically and there is no changeover time as in the conventional casewhere a rubber band is used, besides that the pressing force applied tothe turn-up portions N can be made constant regardless of elapse oftime, whereby a stable tire quality can be secured. Moreover, thestructure of the moving means 75 and the swinging means 76 can besimplified and the manufacturing costs can be reduced.

The operation of the present invention will be explained below withreference to the above-described embodiment.

It is assumed that the sliders 20 are moved together to the radiallyouter limit positions by the rotation of the screw shaft 13. On thisoccasion, since the pistons 31 have been moved to the axially outerlimit positions by the supply of the high pressure fluid into the innercylinder chambers 29A, the bead lock bodies 26 are standing by at theradially inner limit positions. A this time, since the high pressurefluid is supplied to the cylinder chambers 52 through the fluid passages54, the inner and the outer sliders 40, 50 are moved to the axiallyouter limit positions together with the inner end walls 51 in contactwith the outer end walls 47, and with the links 72 swung to the radiallyinner limit positions to be substantially parallel to each other. Bythis, the turn-up arms 66 have been swung to the radially inner limitpositions where the turn-up rollers 70 are in contact with the receivingsurfaces 28.

Subsequently, the cylindrical tire structure member K and the bead Bwith the filler F, formed by another molding drum, and a belt/tread bandT formed on a band forming machine (not shown), are conveyed by aconveying means (not shown) and loosely fitted onto the outer surface ofthe tire building drum 11. At this time, each bead B is placed or set ata predetermined position, particularly radially outside of the lockgroove 27 in the relevant bead lock body 26.

Then, the high pressure fluid is supplied to the outer cylinder chambers29B, so that the pistons 31 and the sliders 32 are moved axially inward,thereby causing the links 34 to swing radially outward, and also causingthe bead lock segments 24 to be synchronously moved radially outwardwhile being guided by the guide rail 23. The movement of the bead lockbodies 26 is stopped when the lock grooves 27 are pressed into contactwith the beads B through the seal members 36 and the tire structuremember K. On this occasion, the tire structure member K is held fromboth sides by the pair of bead lock bodies 26 and the pair of beads B.

Since a low pressure fluid is being supplied to the cylinder chambers52, the turn-up rollers 70 are raised by the receiving surfaces 28, sothat the outer sliders 50 are slightly moved axially inward relative tothe inner slider 40. As a result, the distance between the base ends ofthe turn-up arms 66 and the inner ends of the links 72 is slightlyreduced, thereby causing the turn-up arms 66 to be slightly swungradially outward about the pins 67 and the links 72 to be slightly swungradially outward about the respective inner ends. By this, the turn-uprollers 70 are moved radially outward following the bead lock bodies 26,while maintaining the contact with the receiving surfaces 28 of the beadlock bodies 26.

Next, the screw shaft 13 is rotated so that the sliders 20 are movedaxially inward, i.e., toward each other, and the high pressure fluid issupplied into the tire structure member K between the beads B (i.e.,into the main body portion M). As a result, the main body portion M isexpanded radially outward to have a section with a substantiallysemicircular shape. The outer periphery at the radially outer end of themain body portion M is tightly brought into contact with the innerperiphery of the belt/tread band T. At this time, the turn-up portion Nlocated axially outside from the bead B still maintains the cylindricalshape as shown by the solid lines in FIG. 2.

The high pressure fluid is then supplied into the cylinder chambers 42through the fluid passages 44, and also into the cylinder chambers 56through the supply/discharge passages 59. The inner sliders 40 and theouter sliders 50 hooked by the inner sliders 40 are moved axially inwardtogether, and the outer sliders 50 are further moved axially inwardrelative to the inner slider 40. Here, by the movement of the inner andthe outer sliders 40, 50 axially inward, the turn-up arms 66 and theturn-up rollers 70 are integrally and synchronously moved axiallyinward. Further, by the movement of the outer sliders 50 axially inwardrelative to the inner sliders 40, the turn-up arms 66 and the links 72are synchronously swung radially outward, and the turn-up rollers 70 aremoved radially outward along the arcuate paths about the pins 67.

As a result, the turn-up rollers 70 are moved in the direction combiningthe axially inward movement and the radially outward movement. On thisoccasion, the supply amount of the high pressure fluid into the cylinderchambers 42, 56 is suitably adjusted so that the movement trajectory ofthe above turn-up roller 70 conforms with the shape along the main bodyportion M. By this, the turn-up portions N of the tire structure memberK are turned up by the turn-up rollers 70 in rolling contact with theturn-up portions N radially outward along the main body portion M aroundthe beads B and pressed into contact with the main body portion M so asto build a green tire A.

Since the turn-up arms 66 are synchronously moved by the moving means 75axially inward with the turn-up rollers 70 in contact with the turn-upportions N as described above, while the turn-up arms 66 aresynchronously swung by the swinging means 76 radially outward, thecontact pressure applied by the turn-up rollers 70 to the turn-upportions N (part of the sidewall portions of the green tire A afterbeing turned up) can be easily and positively optimized to a propervalue.

As a result, impressions or grooves generated in the outer surface ofthe turn-up portion N can be made as shallow as possible, such that thegroove can be substantially erased by vulcanization. Moreover,generation of grooves extending in the radial direction on the sidewallportion of the product tire can be easily and effectively restricted.Here, the above-described contact pressure is a resultant force of theaxial force applied by the moving means 75 to the turn-up rollers 70 andthe radial force applied by the swinging means 76 to the turn-up rollers70. The value of this resultant force (contact pressure) can becontrolled easily and positively, by adjusting the supply amount andsupply pressure of the high pressure fluid into the cylinder chambers42, 56.

In the above-described preferred embodiment, the turn-up portions N areturned up after the belt/tread band T has been applied onto the mainbody portion M of the tire structure member K. Alternatively, however,the arrangement may be such that the belt/tread band is applied onto themain body portion after the turn-up portions have been turned up aroundthe bead. In the above-described preferred embodiment, the main bodyportion M is expanded to the substantially semicircular section bydirectly supplying the high pressure fluid into the main body portion M.Alternatively, however, the bladder may be placed in the main bodyportion so that the bladder and the main body portion are expanded tothe substantially semi-circular section by supplying the high pressurefluid into this bladder.

INDUSTRIAL APPLICABILITY

It will be appreciated from the foregoing description that the presentinvention serves to effectively restrict generation of grooves in thesidewall portion of product tires.

1. A method for turning up a tire structure member, wherein a pair ofbeads are supported by a tire building drum from radially inside, andsubstantially cylindrical turn-up portions of the tire structure memberlocated on axially outside of the beads are turned around the beads toextend along a main body portion of the tire structure member locatedbetween the beads and having a substantially semicircular cross-section,with an apparatus including a plurality of turn-up arms spaced from eachother in a peripheral direction and arranged on both outsides of thetire building drum in the axial direction, said turn-up arms each beingadapted to swing in the radial direction around a base end spaced fromthe bead on a plane including the center axis of the tire building drum,and further including turn-up roller rotatably supported by tip ends ofthe turn-up arms, wherein the turn-up arms are moved synchronously by amoving means axially inward, with said turn-up rollers maintained incontact with the turn-up portion, while said turn-up arms are swungsynchronously by a swinging means radially outward so that the turn-upportions are turned around the bead.
 2. An apparatus for turning up atire structure member, wherein a pair of beads are supported by a tirebuilding drum from radially inside, and substantially cylindricalturn-up portions of the tire structure member located on axially outsideof the beads are turned around the beads to extend along a main bodyportion of the tire structure member located between the beads andhaving a substantially semicircular cross-section, said apparatuscomprising: a plurality of turn-up arms spaced from each other in aperipheral direction and arranged on both outsides of the tire buildingdrum in the axial direction, said turn-up arms each being adapted toswing in the radial direction around a base end spaced from the bead ona plane including the center axis of the tire building drum; a pluralityof turn-up rollers rotatably supported by tip ends of the turn-up armsand adapted to achieve rolling contact with the turn-up portion; amoving means for synchronously moving the turn-up arms in the axialdirection; and a swinging means for synchronously swinging the turn-uparms in the radial direction, wherein the turn-up arms are movedsynchronously by a moving means axially inward, with said turn-uprollers maintained in contact with the turn-up portion, while saidturn-up arms are swung synchronously by a swinging means radiallyoutward so that the turn-up portions are turned around the bead.
 3. Theapparatus for turning up a tire structure member according to claim 2,wherein said moving means comprises an inner slider which is movable inthe axial direction, and said swinging means comprises an outer sliderslidably fitted in the inner slider and overlapped with the inner sliderat least at its axially inner end, a plurality of links each having aninner end connected to the inner slider and an outer end rotatablyconnected to a center part in the longitudinal direction of each turn-uparm, and a moving mechanism for axially moving the outer slider relativeto the inner slider.
 4. The apparatus for turning up a tire structuremember according to claim 3, wherein said moving mechanism comprises acylinder chamber formed between the inner slider and the outer slider,and a supply/discharge passage for supplying or discharging a fluid toor from the cylinder chamber.